Coinbase filed its brief in a federal court in New York. In June, the SEC sued the firm, saying it was illegally operating as a national securities exchange, broker and clearing agency without registering with the regulator.

"Our core argument is simple - we do not offer 'investment contracts' as that term has been construed by decades of Supreme Court and other binding precedent," Coinbase's chief legal officer Paul Grewal said in a statement on Twitter.

(Reporting by Jonathan Stempel and Chris Prentice; Editing by Toby Chopra)